It came two days after the announcement of the nuclear agreement with Iran, yet little mention was made on July 16 of the 70th anniversary of the first nuclear explosion, near Alamogordo, New Mexico. The anniversary underscored that the agreement attempts to thwart proliferation of technology seven decades old.

Nuclear-weapons technology has become markedly more sophisticated since 1945. But not so sophisticated that nations with sufficient money and determination cannot master or acquire it. Iran’s determination is probably related to America’s demonstration, in Iraq and Libya, of the perils of not having nuclear weapons.

Critics who think more severe sanctions are achievable and would break Iran’s determination must answer this: When have sanctions caused a large nation to surrender what it considers a vital national-security interest? Critics have, however, amply demonstrated two things:

First, the agreement comprehensively abandons President Obama’s original goal of dismantling the infrastructure of its nuclear-weapons program. Second, as the administration became more yielding with Iran, it became more dishonest with Americans.

For example, John Kerry says we never sought “anywhere, anytime” inspections. But on April 6, Ben Rhodes, Obama’s deputy national security adviser, said the agreement would include “anywhere, anytime” inspections. Kerry’s co-negotiator, Wendy Sherman, breezily dismissed “anywhere, anytime” as “something that became popular rhetoric.” It “became”? This is disgraceful.

During the 1960 campaign, John Kennedy cited “indications” that by 1964 there would be “10, 15 or 20” nuclear powers. As president, he said that by 1975 there might be 15 or 20. Nonproliferation efforts have succeeded but cannot completely succeed forever.

It is a law of arms control: Agreements are impossible until they are unimportant. The US-Soviet strategic-arms-control “process” was an arena of maneuvering for military advantage, until the Soviet Union died of anemia.

Might the agreement with Iran buy sufficient time for Iran to undergo regime modification? Although Kerry speaks of the agreement “guaranteeing” that Iran will not become a nuclear power, it will. But what will Iran be like 15 years hence?

The Obama administration’s wager is that the Iranian regime will be subverted by domestic restiveness. The median age in Iran is 29.5 (in the United States, 37.7; in the European Union, 42.2). More than 60 percent of Iran’s university students, and approximately 70 percent of medical students, are women. Ferment is real.

In 1951, Hannah Arendt, a refugee from Hitler’s Germany, argued bleakly that tyrannies wielding modern instruments of social control (bureaucracies, mass communications) could achieve permanence by conscripting the citizenry’s consciousness, thereby suffocating social change. The 1956 Hungarian Revolution changed her mind: No government can control human nature or “all channels of communication.”

Today’s technologies make nations, including Iran, porous to outside influences; intellectual autarky is impossible. The best that can be said for the Iran agreement is that by somewhat protracting Iran’s path to a weapon it buys time for constructive churning in Iran. Although this is a thin reed on which to lean hopes, the reed is as real as Iran’s nuclear ambitions are apparently nonnegotiable.

The best reason for rejecting the agreement is to rebuke Obama’s long record of aggressive disdain for Congress — recess appointments when the Senate was not in recess, rewriting and circumventing statutes, etc.

Obama’s intellectual pedigree runs to Woodrow Wilson, the first presidential disparager of the separation of powers. Like Wilson, Obama ignores the constitutional etiquette of respecting even rivalrous institutions.

The Iran agreement should be a treaty; it should not have been submitted first to the United Nations as a studied insult to Congress.

Wilson said that rejecting the Versailles Treaty would “break the heart of the world.” The Senate, no member of which had been invited to accompany Wilson to the Paris Peace Conference, proceeded to break his heart.